Merge branch 'develop'

1 files changed, 237 insertions, 412 deletions

diff --git a/lib/leap_cli/commands/ca.rb b/lib/leap_cli/commands/ca.rb
index 1b311eee..3c5fc7d5 100644
--- a/lib/leap_cli/commands/ca.rb
+++ b/lib/leap_cli/commands/ca.rb
@@ -1,8 +1,3 @@
-autoload :OpenSSL, 'openssl'
-autoload :CertificateAuthority, 'certificate_authority'
-autoload :Date, 'date'
-require 'digest/md5'
-
 module LeapCli; module Commands
 
   desc "Manage X.509 certificates"
@@ -35,41 +30,15 @@ module LeapCli; module Commands
     cert.desc 'Creates a Diffie-Hellman parameter file, needed for forward secret OpenVPN ciphers.' # (needed for server-side of some TLS connections)
     cert.command :dh do |dh|
       dh.action do |global_options,options,args|
-        long_running do
-          if cmd_exists?('certtool')
-            log 0, 'Generating DH parameters (takes a long time)...'
-            output = assert_run!('certtool --generate-dh-params --sec-param high')
-            output.sub! /.*(-----BEGIN DH PARAMETERS-----.*-----END DH PARAMETERS-----).*/m, '\1'
-            output << "\n"
-            write_file!(:dh_params, output)
-          else
-            log 0, 'Generating DH parameters (takes a REALLY long time)...'
-            output = OpenSSL::PKey::DH.generate(3248).to_pem
-            write_file!(:dh_params, output)
-          end
-        end
+        generate_dh
       end
     end
 
-    #
-    # hints:
-    #
-    # inspect CSR:
-    #   openssl req -noout -text -in files/cert/x.csr
-    #
-    # generate CSR with openssl to see how it compares:
-    #   openssl req -sha256 -nodes -newkey rsa:2048 -keyout example.key -out example.csr
-    #
-    # validate a CSR:
-    #   http://certlogik.com/decoder/
-    #
-    # nice details about CSRs:
-    #   http://www.redkestrel.co.uk/Articles/CSR.html
-    #
     cert.desc "Creates a CSR for use in buying a commercial X.509 certificate."
     cert.long_desc "Unless specified, the CSR is created for the provider's primary domain. "+
       "The properties used for this CSR come from `provider.ca.server_certificates`, "+
       "but may be overridden here."
+    cert.arg_name "DOMAIN"
     cert.command :csr do |csr|
       csr.flag 'domain', :arg_name => 'DOMAIN', :desc => 'Specify what domain to create the CSR for.'
       csr.flag ['organization', 'O'], :arg_name => 'ORGANIZATION', :desc => "Override default O in distinguished name."
@@ -81,70 +50,26 @@ module LeapCli; module Commands
       csr.flag :bits, :arg_name => 'BITS', :desc => "Override default certificate bit length"
       csr.flag :digest, :arg_name => 'DIGEST', :desc => "Override default signature digest"
       csr.action do |global_options,options,args|
-        assert_config! 'provider.domain'
-        assert_config! 'provider.name'
-        assert_config! 'provider.default_language'
-        assert_config! 'provider.ca.server_certificates.bit_size'
-        assert_config! 'provider.ca.server_certificates.digest'
-        domain = options[:domain] || provider.domain
-
-        unless global_options[:force]
-          assert_files_missing! [:commercial_key, domain], [:commercial_csr, domain],
-            :msg => 'If you really want to create a new key and CSR, remove these files first or run with --force.'
-        end
-
-        server_certificates = provider.ca.server_certificates
-
-        # RSA key
-        keypair = CertificateAuthority::MemoryKeyMaterial.new
-        bit_size = (options[:bits] || server_certificates.bit_size).to_i
-        log :generating, "%s bit RSA key" % bit_size do
-          keypair.generate_key(bit_size)
-          write_file! [:commercial_key, domain], keypair.private_key.to_pem
-        end
-
-        # CSR
-        dn  = CertificateAuthority::DistinguishedName.new
-        dn.common_name   = domain
-        dn.organization  = options[:organization] || provider.name[provider.default_language]
-        dn.ou            = options[:organizational_unit] # optional
-        dn.email_address = options[:email] # optional
-        dn.country       = options[:country] || server_certificates['country']   # optional
-        dn.state         = options[:state] || server_certificates['state']       # optional
-        dn.locality      = options[:locality] || server_certificates['locality'] # optional
-
-        digest = options[:digest] || server_certificates.digest
-        log :generating, "CSR with #{digest} digest and #{print_dn(dn)}" do
-          csr = create_csr(dn, keypair, digest)
-          request = csr.to_x509_csr
-          write_file! [:commercial_csr, domain], csr.to_pem
-        end
+        generate_csr(global_options, options, args)
+      end
+    end
 
-        # Sign using our own CA, for use in testing but hopefully not production.
-        # It is not that commerical CAs are so secure, it is just that signing your own certs is
-        # a total drag for the user because they must click through dire warnings.
-        #if options[:sign]
-          log :generating, "self-signed x509 server certificate for testing purposes" do
-            cert = csr.to_cert
-            cert.serial_number.number = cert_serial_number(domain)
-            cert.not_before = yesterday
-            cert.not_after  = yesterday.advance(:years => 1)
-            cert.parent = ca_root
-            cert.sign! domain_test_signing_profile
-            write_file! [:commercial_cert, domain], cert.to_pem
-            log "please replace this file with the real certificate you get from a CA using #{Path.relative_path([:commercial_csr, domain])}"
-          end
-        #end
+    cert.desc "Register an authorization key with the CA letsencrypt.org"
+    cert.long_desc "This only needs to be done once."
+    cert.command :register do |register|
+      register.action do |global, options, args|
+        do_register_key(global, options, args)
+      end
+    end
 
-        # FAKE CA
-        unless file_exists? :commercial_ca_cert
-          log :using, "generated CA in place of commercial CA for testing purposes" do
-            write_file! :commercial_ca_cert, read_file!(:ca_cert)
-            log "please also replace this file with the CA cert from the commercial authority you use."
-          end
-        end
+    cert.desc "Renews a certificate using the CA letsencrypt.org"
+    cert.arg_name "DOMAIN"
+    cert.command :renew do |renew|
+      renew.action do |global, options, args|
+        do_renew_cert(global, options, args)
       end
     end
+
   end
 
   protected
@@ -153,6 +78,7 @@ module LeapCli; module Commands
   # will generate new certificates for the specified nodes, if needed.
   #
   def update_certificates(nodes, options={})
+    require 'leap_cli/x509'
     assert_files_exist! :ca_cert, :ca_key, :msg => 'Run `leap cert ca` to create them'
     assert_config! 'provider.ca.server_certificates.bit_size'
     assert_config! 'provider.ca.server_certificates.digest'
@@ -160,382 +86,281 @@ module LeapCli; module Commands
     assert_config! 'common.x509.use'
 
     nodes.each_node do |node|
-      warn_if_commercial_cert_will_soon_expire(node)
+      node.warn_if_commercial_cert_will_soon_expire
       if !node.x509.use
         remove_file!([:node_x509_key, node.name])
         remove_file!([:node_x509_cert, node.name])
-      elsif options[:force] || cert_needs_updating?(node)
-        generate_cert_for_node(node)
+      elsif options[:force] || node.cert_needs_updating?
+        node.generate_cert
       end
     end
   end
 
+  #
+  # yields client key and cert suitable for testing
+  #
+  def generate_test_client_cert(prefix=nil)
+    require 'leap_cli/x509'
+    cert = CertificateAuthority::Certificate.new
+    cert.serial_number.number = cert_serial_number(provider.domain)
+    cert.subject.common_name = [prefix, random_common_name(provider.domain)].join
+    cert.not_before = X509.yesterday
+    cert.not_after  = X509.yesterday.advance(:years => 1)
+    cert.key_material.generate_key(1024) # just for testing, remember!
+    cert.parent = client_ca_root
+    cert.sign! client_test_signing_profile
+    yield cert.key_material.private_key.to_pem, cert.to_pem
+  end
+
   private
 
   def generate_new_certificate_authority(key_file, cert_file, common_name)
+    require 'leap_cli/x509'
     assert_files_missing! key_file, cert_file
     assert_config! 'provider.ca.name'
     assert_config! 'provider.ca.bit_size'
     assert_config! 'provider.ca.life_span'
 
-    root = CertificateAuthority::Certificate.new
+    root = X509.new_ca(provider.ca, common_name)
 
-    # set subject
-    root.subject.common_name = common_name
-    possible = ['country', 'state', 'locality', 'organization', 'organizational_unit', 'email_address']
-    provider.ca.keys.each do |key|
-      if possible.include?(key)
-        root.subject.send(key + '=', provider.ca[key])
+    write_file!(key_file, root.key_material.private_key.to_pem)
+    write_file!(cert_file, root.to_pem)
+  end
+
+  def generate_dh
+    require 'leap_cli/x509'
+    long_running do
+      if cmd_exists?('certtool')
+        log 0, 'Generating DH parameters (takes a long time)...'
+        output = assert_run!('certtool --generate-dh-params --sec-param high')
+        output.sub!(/.*(-----BEGIN DH PARAMETERS-----.*-----END DH PARAMETERS-----).*/m, '\1')
+        output << "\n"
+        write_file!(:dh_params, output)
+      else
+        log 0, 'Generating DH parameters (takes a REALLY long time)...'
+        output = OpenSSL::PKey::DH.generate(3248).to_pem
+        write_file!(:dh_params, output)
       end
     end
+  end
 
-    # set expiration
-    root.not_before = yesterday
-    root.not_after = yesterday_advance(provider.ca.life_span)
-
-    # generate private key
-    root.serial_number.number = 1
-    root.key_material.generate_key(provider.ca.bit_size)
+  #
+  # hints:
+  #
+  # inspect CSR:
+  #   openssl req -noout -text -in files/cert/x.csr
+  #
+  # generate CSR with openssl to see how it compares:
+  #   openssl req -sha256 -nodes -newkey rsa:2048 -keyout example.key -out example.csr
+  #
+  # validate a CSR:
+  #   http://certlogik.com/decoder/
+  #
+  # nice details about CSRs:
+  #   http://www.redkestrel.co.uk/Articles/CSR.html
+  #
+  def generate_csr(global_options, options, args)
+    require 'leap_cli/x509'
+    assert_config! 'provider.domain'
+    assert_config! 'provider.name'
+    assert_config! 'provider.default_language'
+    assert_config! 'provider.ca.server_certificates.bit_size'
+    assert_config! 'provider.ca.server_certificates.digest'
 
-    # sign self
-    root.signing_entity = true
-    root.parent = root
-    root.sign!(ca_root_signing_profile)
+    server_certificates      = provider.ca.server_certificates
+    options[:domain]       ||= args.first || provider.domain
+    options[:organization] ||= provider.name[provider.default_language]
+    options[:country]      ||= server_certificates['country']
+    options[:state]        ||= server_certificates['state']
+    options[:locality]     ||= server_certificates['locality']
+    options[:bits]         ||= server_certificates.bit_size
+    options[:digest]       ||= server_certificates.digest
+
+    unless global_options[:force]
+      assert_files_missing! [:commercial_key, options[:domain]], [:commercial_csr, options[:domain]],
+        :msg => 'If you really want to create a new key and CSR, remove these files first or run with --force.'
+    end
 
-    # save
-    write_file!(key_file, root.key_material.private_key.to_pem)
-    write_file!(cert_file, root.to_pem)
+    X509.create_csr_and_cert(options)
   end
 
   #
-  # returns true if the certs associated with +node+ need to be regenerated.
+  # letsencrypt.org
   #
-  def cert_needs_updating?(node)
-    if !file_exists?([:node_x509_cert, node.name], [:node_x509_key, node.name])
-      return true
-    else
-      cert = load_certificate_file([:node_x509_cert, node.name])
-      if !created_by_authority?(cert, ca_root)
-        log :updating, "cert for node '#{node.name}' because it was signed by an old CA root cert."
-        return true
-      end
-      if cert.not_after < Time.now.advance(:months => 2)
-        log :updating, "cert for node '#{node.name}' because it will expire soon"
-        return true
-      end
-      if cert.subject.common_name != node.domain.full
-        log :updating, "cert for node '#{node.name}' because domain.full has changed (was #{cert.subject.common_name}, now #{node.domain.full})"
-        return true
+
+  def do_register_key(global, options, args)
+    require 'leap_cli/acme'
+    assert_config! 'provider.contacts.default'
+    contact = manager.provider.contacts.default.first
+
+    if file_exists?(:acme_key) && !global[:force]
+      bail! do
+        log "the authorization key for letsencrypt.org already exists"
+        log "run with --force if you really want to register a new key."
       end
-      cert.openssl_body.extensions.each do |ext|
-        if ext.oid == "subjectAltName"
-          ips = []
-          dns_names = []
-          ext.value.split(",").each do |value|
-            value.strip!
-            ips << $1          if value =~ /^IP Address:(.*)$/
-            dns_names << $1    if value =~ /^DNS:(.*)$/
-          end
-          dns_names.sort!
-          if ips.first != node.ip_address
-            log :updating, "cert for node '#{node.name}' because ip_address has changed (from #{ips.first} to #{node.ip_address})"
-            return true
-          elsif dns_names != dns_names_for_node(node)
-            log :updating, "cert for node '#{node.name}' because domain name aliases have changed\n    from: #{dns_names.inspect}\n    to: #{dns_names_for_node(node).inspect})"
-            return true
-          end
+    else
+      private_key = Acme.new_private_key
+      registration = nil
+
+      log(:registering, "letsencrypt.org authorization key using contact `%s`" % contact) do
+        acme = Acme.new(key: private_key)
+        registration = acme.register(contact)
+        if registration
+          log 'success!', :color => :green, :style => :bold
+        else
+          bail! "could not register authorization key."
         end
       end
-    end
-    return false
-  end
 
-  def created_by_authority?(cert, ca)
-    authority_key_id = cert.extensions["authorityKeyIdentifier"].identifier.sub(/^keyid:/, '')
-    authority_key_id == public_key_id_for_ca(ca)
-  end
-
-  # calculate the "key id" for a root CA, that matches the value
-  # Authority Key Identifier in the x509 extensions of a cert.
-  def public_key_id_for_ca(ca_cert)
-    @ca_key_ids ||= {}
-    @ca_key_ids[ca_cert.object_id] ||= begin
-      pubkey = ca_cert.key_material.public_key
-      seq = OpenSSL::ASN1::Sequence([
-        OpenSSL::ASN1::Integer.new(pubkey.n),
-        OpenSSL::ASN1::Integer.new(pubkey.e)
-      ])
-      Digest::SHA1.hexdigest(seq.to_der).upcase.scan(/../).join(':')
+      log :saving, "authorization key for letsencrypt.org" do
+        write_file!(:acme_key, private_key.to_pem)
+        write_file!(:acme_info, JSON.sorted_generate({
+          id: registration.id,
+          contact: registration.contact,
+          key: registration.key,
+          uri: registration.uri
+        }))
+        log :warning, "keep key file private!"
+      end
     end
   end
 
-  def warn_if_commercial_cert_will_soon_expire(node)
-    dns_names_for_node(node).each do |domain|
-      if file_exists?([:commercial_cert, domain])
-        cert = load_certificate_file([:commercial_cert, domain])
-        path = Path.relative_path([:commercial_cert, domain])
-        if cert.not_after < Time.now.utc
-          log :error, "the commercial certificate '#{path}' has EXPIRED! " +
-            "You should renew it with `leap cert csr --domain #{domain}`."
-        elsif cert.not_after < Time.now.advance(:months => 2)
-          log :warning, "the commercial certificate '#{path}' will expire soon (#{cert.not_after}). "+
-            "You should renew it with `leap cert csr --domain #{domain}`."
-        end
-      end
+  def assert_no_errors!(msg)
+    yield
+  rescue StandardError => exc
+    bail! :error, msg do
+      log exc.to_s
     end
   end
 
-  def generate_cert_for_node(node)
-    return if node.x509.use == false
-
-    cert = CertificateAuthority::Certificate.new
-
-    # set subject
-    cert.subject.common_name = node.domain.full
-    cert.serial_number.number = cert_serial_number(node.domain.full)
+  def do_renew_cert(global, options, args)
+    require 'leap_cli/acme'
+    require 'leap_cli/ssh'
+    require 'socket'
+    require 'net/http'
 
-    # set expiration
-    cert.not_before = yesterday
-    cert.not_after = yesterday_advance(provider.ca.server_certificates.life_span)
+    csr = nil
+    account_key = nil
+    cert = nil
+    acme = nil
 
-    # generate key
-    cert.key_material.generate_key(provider.ca.server_certificates.bit_size)
-
-    # sign
-    cert.parent = ca_root
-    cert.sign!(server_signing_profile(node))
-
-    # save
-    write_file!([:node_x509_key, node.name], cert.key_material.private_key.to_pem)
-    write_file!([:node_x509_cert, node.name], cert.to_pem)
-  end
-
-  #
-  # yields client key and cert suitable for testing
-  #
-  def generate_test_client_cert(prefix=nil)
-    cert = CertificateAuthority::Certificate.new
-    cert.serial_number.number = cert_serial_number(provider.domain)
-    cert.subject.common_name = [prefix, random_common_name(provider.domain)].join
-    cert.not_before = yesterday
-    cert.not_after  = yesterday.advance(:years => 1)
-    cert.key_material.generate_key(1024) # just for testing, remember!
-    cert.parent = client_ca_root
-    cert.sign! client_test_signing_profile
-    yield cert.key_material.private_key.to_pem, cert.to_pem
-  end
-
-  #
-  # creates a CSR and returns it.
-  # with the correct extReq attribute so that the CA
-  # doens't generate certs with extensions we don't want.
-  #
-  def create_csr(dn, keypair, digest)
-    csr = CertificateAuthority::SigningRequest.new
-    csr.distinguished_name = dn
-    csr.key_material = keypair
-    csr.digest = digest
-
-    # define extensions manually (library doesn't support setting these on CSRs)
-    extensions = []
-    extensions << CertificateAuthority::Extensions::BasicConstraints.new.tap {|basic|
-      basic.ca = false
-    }
-    extensions << CertificateAuthority::Extensions::KeyUsage.new.tap {|keyusage|
-      keyusage.usage = ["digitalSignature", "keyEncipherment"]
-    }
-    extensions << CertificateAuthority::Extensions::ExtendedKeyUsage.new.tap {|extkeyusage|
-      extkeyusage.usage = [ "serverAuth"]
-    }
-
-    # convert extensions to attribute 'extReq'
-    # aka "Requested Extensions"
-    factory = OpenSSL::X509::ExtensionFactory.new
-    attrval = OpenSSL::ASN1::Set([OpenSSL::ASN1::Sequence(
-      extensions.map{|e| factory.create_ext(e.openssl_identifier, e.to_s, e.critical)}
-    )])
-    attrs = [
-      OpenSSL::X509::Attribute.new("extReq", attrval),
-    ]
-    csr.attributes = attrs
-
-    return csr
-  end
+    #
+    # sanity check the domain
+    #
+    domain = args.first
+    nodes  = nodes_for_domain(domain)
+    domain_ready_for_acme!(domain)
 
-  def ca_root
-    @ca_root ||= begin
-      load_certificate_file(:ca_cert, :ca_key)
+    #
+    # load key material
+    #
+    assert_files_exist!([:commercial_key, domain], [:commercial_csr, domain],
+      :msg => 'Please create the CSR first with `leap cert csr %s`' % domain)
+    assert_no_errors!("Could not load #{path([:commercial_csr, domain])}") do
+      csr = Acme.load_csr(read_file!([:commercial_csr, domain]))
     end
-  end
-
-  def client_ca_root
-    @client_ca_root ||= begin
-      load_certificate_file(:client_ca_cert, :client_ca_key)
+    assert_files_exist!(:acme_key,
+      :msg => "Please run `leap cert register` first. This only needs to be done once.")
+    assert_no_errors!("Could not load #{path(:acme_key)}") do
+      account_key = Acme.load_private_key(read_file!(:acme_key))
     end
-  end
 
-  def load_certificate_file(crt_file, key_file=nil, password=nil)
-    crt = read_file!(crt_file)
-    openssl_cert = OpenSSL::X509::Certificate.new(crt)
-    cert = CertificateAuthority::Certificate.from_openssl(openssl_cert)
-    if key_file
-      key = read_file!(key_file)
-      cert.key_material.private_key = OpenSSL::PKey::RSA.new(key, password)
+    #
+    # check authorization for this domain
+    #
+    log :checking, "authorization"
+    acme = Acme.new(domain: domain, key: account_key)
+    status, message = acme.authorize do |challenge|
+      log(:uploading, 'challenge to server %s' % domain) do
+        SSH.remote_command(nodes) do |ssh, host|
+          ssh.scripts.upload_acme_challenge(challenge.token, challenge.file_content)
+        end
+      end
+      log :waiting, "for letsencrypt.org to verify challenge"
+    end
+    if status == 'valid'
+      log 'authorized!', color: :green, style: :bold
+    elsif status == 'error'
+      bail! :error, message
+    elsif status == 'unauthorized'
+      bail!(:unauthorized, message, color: :yellow, style: :bold) do
+        log 'You must first run `leap cert register` to register the account key with letsencrypt.org'
+      end
     end
-    return cert
-  end
-
-  def ca_root_signing_profile
-    {
-      "extensions" => {
-        "basicConstraints" => {"ca" => true},
-        "keyUsage" => {
-          "usage" => ["critical", "keyCertSign"]
-        },
-        "extendedKeyUsage" => {
-          "usage" => []
-        }
-      }
-    }
-  end
 
-  #
-  # For keyusage, openvpn server certs can have keyEncipherment or keyAgreement.
-  # Web browsers seem to break without keyEncipherment.
-  # For now, I am using digitalSignature + keyEncipherment
-  #
-  # * digitalSignature -- for (EC)DHE cipher suites
-  #   "The digitalSignature bit is asserted when the subject public key is used
-  #    with a digital signature mechanism to support security services other
-  #    than certificate signing (bit 5), or CRL signing (bit 6). Digital
-  #    signature mechanisms are often used for entity authentication and data
-  #    origin authentication with integrity."
-  #
-  # * keyEncipherment  ==> for plain RSA cipher suites
-  #   "The keyEncipherment bit is asserted when the subject public key is used for
-  #    key transport. For example, when an RSA key is to be used for key management,
-  #    then this bit is set."
-  #
-  # * keyAgreement     ==> for used with DH, not RSA.
-  #   "The keyAgreement bit is asserted when the subject public key is used for key
-  #    agreement. For example, when a Diffie-Hellman key is to be used for key
-  #    management, then this bit is set."
-  #
-  # digest options: SHA512, SHA256, SHA1
-  #
-  def server_signing_profile(node)
-    {
-      "digest" => provider.ca.server_certificates.digest,
-      "extensions" => {
-        "keyUsage" => {
-          "usage" => ["digitalSignature", "keyEncipherment"]
-        },
-        "extendedKeyUsage" => {
-          "usage" => ["serverAuth", "clientAuth"]
-        },
-        "subjectAltName" => {
-          "ips" => [node.ip_address],
-          "dns_names" => dns_names_for_node(node)
-        }
-      }
-    }
+    log :fetching, "new certificate from letsencrypt.org"
+    assert_no_errors!("could not renew certificate") do
+      cert = acme.get_certificate(csr)
+    end
+    log 'success', color: :green, style: :bold
+    write_file!([:commercial_cert, domain], cert.fullchain_to_pem)
+    log 'You should now run `leap deploy` to deploy the new certificate.'
   end
 
   #
-  # This is used when signing the main cert for the provider's domain
-  # with our own CA (for testing purposes). Typically, this cert would
-  # be purchased from a commercial CA, and not signed this way.
+  # Returns a hash of nodes that match this domain. It also checks:
   #
-  def domain_test_signing_profile
-    {
-      "digest" => "SHA256",
-      "extensions" => {
-        "keyUsage" => {
-          "usage" => ["digitalSignature", "keyEncipherment"]
-        },
-        "extendedKeyUsage" => {
-          "usage" => ["serverAuth"]
-        }
-      }
-    }
-  end
-
+  # * a node configuration has this domain
+  # * the dns for the domain exists
   #
-  # This is used when signing a dummy client certificate that is only to be
-  # used for testing.
+  # This method will bail if any checks fail.
   #
-  def client_test_signing_profile
-    {
-      "digest" => "SHA256",
-      "extensions" => {
-        "keyUsage" => {
-          "usage" => ["digitalSignature"]
-        },
-        "extendedKeyUsage" => {
-          "usage" => ["clientAuth"]
-        }
-      }
-    }
-  end
-
-  def dns_names_for_node(node)
-    names = [node.domain.internal, node.domain.full]
-    if node['dns'] && node.dns['aliases'] && node.dns.aliases.any?
-      names += node.dns.aliases
+  def nodes_for_domain(domain)
+    bail! { log 'Argument DOMAIN is required' } if domain.nil? || domain.empty?
+    nodes = manager.nodes['dns.aliases' => domain]
+    if nodes.empty?
+      bail! :error, "There are no nodes configured for domain `%s`" % domain
     end
-    names.compact!
-    names.sort!
-    names.uniq!
-    return names
+    begin
+      ips = Socket.getaddrinfo(domain, 'http').map {|record| record[2]}.uniq
+      nodes = nodes['ip_address' => ips]
+      if nodes.empty?
+        bail! do
+          log :error, "The domain `%s` resolves to [%s]" % [domain, ips.join(', ')]
+          log :error, "But there no nodes configured for this domain with these adddresses."
+        end
+      end
+    rescue SocketError
+      bail! :error, "Could not resolve the DNS for `#{domain}`. Without a DNS " +
+        "entry for this domain, authorization will not work."
+    end
+    return nodes
   end
 
   #
-  # For cert serial numbers, we need a non-colliding number less than 160 bits.
-  # md5 will do nicely, since there is no need for a secure hash, just a short one.
-  # (md5 is 128 bits)
+  # runs the following checks on the domain:
   #
-  def cert_serial_number(domain_name)
-    Digest::MD5.hexdigest("#{domain_name} -- #{Time.now}").to_i(16)
-  end
-
+  # * we are able to get /.well-known/acme-challenge/ok
   #
-  # for the random common name, we need a text string that will be unique across all certs.
-  # ruby 1.8 doesn't have a built-in uuid generator, or we would use SecureRandom.uuid
+  # This method will bail if any checks fail.
   #
-  def random_common_name(domain_name)
-    cert_serial_number(domain_name).to_s(36)
-  end
-
-  # prints CertificateAuthority::DistinguishedName fields
-  def print_dn(dn)
-    fields = {}
-    [:common_name, :locality, :state, :country, :organization, :organizational_unit, :email_address].each do |attr|
-      fields[attr] = dn.send(attr) if dn.send(attr)
-    end
-    fields.inspect
-  end
-
-  ##
-  ## TIME HELPERS
-  ##
-  ## note: we use 'yesterday' instead of 'today', because times are in UTC, and some people on the planet
-  ## are behind UTC.
-  ##
-
-  def yesterday
-    t = Time.now - 24*24*60
-    Time.utc t.year, t.month, t.day
-  end
-
-  def yesterday_advance(string)
-    number, unit = string.split(' ')
-    unless ['years', 'months', 'days', 'hours', 'minutes'].include? unit
-      bail!("The time property '#{string}' is missing a unit (one of: years, months, days, hours, minutes).")
-    end
-    unless number.to_i.to_s == number
-      bail!("The time property '#{string}' is missing a number.")
+  def domain_ready_for_acme!(domain)
+    begin
+      uri = URI("https://#{domain}/.well-known/acme-challenge/ok")
+      options = {
+        use_ssl: true,
+        open_timeout: 5,
+        verify_mode: OpenSSL::SSL::VERIFY_NONE
+      }
+      Net::HTTP.start(uri.host, uri.port, options) do |http|
+        http.request(Net::HTTP::Get.new(uri)) do |response|
+          if !response.is_a?(Net::HTTPSuccess)
+            bail!(:error, "Could not GET %s" % uri) do
+              log "%s %s" % [response.code, response.message]
+              log "You may need to run `leap deploy`"
+            end
+          end
+        end
+      end
+    rescue Errno::ETIMEDOUT, Net::OpenTimeout
+      bail! :error, "Connection attempt timed out: %s" % uri
+    rescue Interrupt
+      bail!
+    rescue StandardError => exc
+      bail!(:error, "Could not GET %s" % uri) do
+        log exc.to_s
+      end
     end
-    yesterday.advance(unit.to_sym => number.to_i)
   end
 
 end; end